Cohort Study
An observational study that follows a defined group of participants over time to examine the relationship between a drug exposure and health outcomes. Cohort studies provide real-world evidence that complements clinical trial data and are valuable for studying long-term safety.
Technical Context
Prospective cohorts follow participants forward from exposure to outcome (higher quality, can establish temporal sequence, but slow and expensive). Retrospective cohorts use historical data (faster and cheaper, but limited by available data quality). Large healthcare database cohort studies using electronic medical records (EMR), insurance claims, and national registries have become important for peptide drug post-marketing safety surveillance. Examples: cohort studies using Scandinavian national health registries examined long-term outcomes of GnRH agonist therapy; insurance claims databases tracked GLP-1 RA users for pancreatic and thyroid safety signals. Cohort studies cannot eliminate confounding (observational, not randomised) — propensity score matching and instrumental variable methods partially address this limitation.